January 31, 2025. If you are a RFH, then you might be in trouble!

So, what is an RFH? That my friend is a Radical Fundamentalist Homebrewer or a person who totally homebrews a rig with discrete parts, no SMD, no chips or Arduinos here. The trouble is that the supply system is doing you in!

A blog reader suggested I go to Digi-Key and search on BF998 which used to be a staple Dual Gate MOSFET, and one often used by W7ZOI. I did that and found out they are not available being obsolete. Aha --click on the link for substitutes and I did that.

Surprise! There is Zero stock, and the subs are also obsolete.

At play here are four factors that will affect our RFH. The first is a demand issue and the basic question who is buying the BF998 DGM for use in production or projects? The answer is a few RFH's or someone who stumbled upon an article in QRP Quarterly by N6QW who designed a two band Direct Conversion Receiver using the BF998. Another user may be looking for a replacement part in an obsolete radio but that is peanuts. No new designs are in process that will use the BF998 or any DGM.

The second factor is cost which the low volume usage drives the price to something above the gag level. What used to cost less than $1 now may hit $10 if you can find it. Just like my recent look at building a LPF with Silver Mica Caps that would each cost $3 or $4. The Polypropylene ones were less than a buck. But there is no less than a buck subs for the DGM's without making one from two J310's. 

But then that raises the third problem as more and more common parts are surface mount only which likely is incompatible with the glue down pads favored by RFH's AKA Manhattan Construction. Most current stock of the J310's is now SMD.

The fourth problem is the seismic technology shift to vertical integration of digital electronics into the ham world. Less and less devices that were once the staple of LC VFO's like coils, NPO or COG Capacitors or even through hole J310's are found in rig designs. Today it is an embedded Microcontroller with a Si5351. The fourth problem goes further by addressing the shift in topology from Hardware Defined Radios to Software Defined Radios. The refined SDR approach using DDC has no BF998's or J310's -- it is all software and digital electronics.

So, up front a tip of the cap to the RFH's who can build a rig that puts out a good quality signal and hold its own on today's bands with stations using a GPS synched frequency scheme capable of telling the RFH you are three hertz low. Indeed, it takes skill, knowledge, perseverance and a real sense of adventure to be an RFH. But cutting off the supply of once common and low-cost, through hole parts make Radically Fundamentalist Homebrewing a very difficult task.

In contrast to our DGM, the MC1496, a through hole Double Balanced Mixer, is a 50-year-old part can still be had at less than $2 in single pieces from Jameco Electronics. The SMD version is half that cost. But that does the RFH no good because it is a chip and the cheap one SMD. But his alternative is a homebrew DBM using four diodes and two cores is still a good solution.

Simple End Message: The times are changing and keeping the rigid principle of "homebrew all" has just been made a bit harder. Add in the self-inflicted tariffs and the hobby may shift to the sport of kings!

Them that know can make it go.

73's

Pete N6QW

January 30, 2025. Low Power Consumption SSB Module.

Low Power Consumption Homebrew Rig for Use During PSPS. Prompted by the 4 recent preemptive "turning out the lights events" we are looking for the better mousetrap.

 

The Starting Place

  

One of the two G4GXO stages.

The 4X6 Board is a complete Receiver less the BPF, LO and BFO

Two of the G4GXO bidirectional modules (Jan 26th posting) are used in this rig. No RF Amp Stage is used to conserve power. What you see and hear is the antenna into the BPF and then on to the Mixer and IF Module. From there onto the Product Detector / Balanced Modulator and audio stages. The Rx/Tx Mixer is a TUF-1, and the PD/BM is an ADE-1. The LO/BFO is a Seed Xiao RP2040 driving a Si5351. The transmit chain will be a 2N2222A, 2N2219A. With 8 Volts PTP output from the 2N2219A that gives about 150 Milliwatts to the antenna on 40M SSB. If we could get 10V PTP then that is a quarter of a watt.

A small relay applies a set level of bias for IF gain on the 1st stage for Receive. On Transmit this stage is then the second IF amp and the relay lets it run wide open.

BTW, I am using a 3N209 in lieu of using the two J310's. A 40673 or BF991 would work well in this circuit. Forget the BF998 as it has too low of a Drain voltage and you would waste power using a voltage regulator to get 5 or 6 volts for operation.

What you see in the really short video is only a starting place. The current hog is the Juliano Blue LCD and the Seed Xiao RP2040. This needs to use something like a non-backlit LCD and the capability to turn off the display. A Pro-Mini MCU may draw less power.

I will take some current draw measurements and make a subsequent posting about those values. At 4:30AM, the garage is like a freezer as the OAT is 41F.

I braved the cold, and the Board draws about 300 milliamps on receive. The Digital LO and BFO plus display another 300 milliamps, so our starting point is to get that down to less than 400ma total. There are some three terminal voltage regulators and relays that draw lots of current and those too need a replacement.

Them that know can make it go.

73's

Pete N6QW

January 29, 2025. A terribly Unhappy Camper

Failure to know something is one thing but being at the other end of a Help Line and knowing nothing about the subject is pure incompetence.

The recent power shutoffs and local fire danger prompted me to remove the "land line" bundled with Frontier and move that to T-Mobile. My Frontier service was out but the T-Mobile worked. I was able to tether my laptop to the T-Mobile phone, so I was good for comms.

Then the trouble started! To unbundle the "land line" phone resulted in Frontier cancelling my service. That was a blessing in disguise. Frontier has essentially screwed me over for a long time. I found out yesterday that instead of paying $134 for the bundle package and by dropping the phone that the bundled cost could be $39. That is robbery! If you have Frontier, I suggest you look carefully at your billing as you too are getting screwed.

So, the alternative is T-Mobile Home Internet. I found that with some recent changes to their cell towers I get a rock-solid signal at my home QTH. This coupled with the tethering usage convinced me that a wireless solution would work here. So, I signed up for the extended wireless router and that will cost me $45/month. I am saving a ton of money.

T-Mobile also has problems. So now to set up the Home Internet you must have the brand-new app called T-Life. I downloaded the app and to use the app you must have the biometric feature installed on your phone. I prefer the old enter the password method. So, I installed the biometric reader.

On the screen for T-Life there was garbage about resetting the password -- I didn't have a password. So, a call to 611. This nice YL in the Philippines' said I will help you. The T-Life screen is not user friendly. So, we get to the part about the reset of the password. Joyce (the YL) sends me a temporary password, and I enter my new password which must be 8 to 50 characters long and contain at least 1 letter and 1 number. Well, that didn't work! We tried all kinds of matching passwords using capital letters and symbols -- but the save button was greyed out. After 30 minutes a brief hold. 

Then she says did you use the biometrics -- I said yes because when you launch the app it directs you to activate the biometrics. Oh, she says that is why you can't reset the password. You are already in the app!

So, thinking ahead I ask OK where the info is for setting up the Home Internet. She said on the screen. She says look at the bottom and there is a tab marked Connect. Well, that connect is not for setting up the system. At the top is a tab marked Internet and that is the one. I told her I didn't trust their app so could you send me the instructions, before I get the router so I can see what is involved. Quote: I am sending them to your email now -- then I ask her to verify the email. I never got the instructions. Why do they make it so hard. 

They don't know so they can't make it go!

73's

Pete N6QW

January 28, 2025. A Revisit to the Hallicrafters FPM-300 Converted to a SS QRP Radio

 

Fumbling the ball. That is what Hallicrafters did in the early 1970's when they introduced the FPM-300 Safari. This radio was an all band SSB CW transceiver with built in power supplies for 12VDC and 120VAC, thus the connection to a Safari. A Hybrid rig, it has two tubes and the rest solid state. 

The fumbling part involves a cranky drifty VFO and a rubber band operated band switch where the rubber band would fail, and the band switch got out of sync.

 

I bought one 10 years ago and could never fix all of the problems, so I kept the main board and S Meter and sold the rest as parts. From these two pieces I designed a solid state QRP radio. The receiver is actually pretty good once you rid yourself of the albatross Hallicrafters circuits associated with the VFO and band switch.

My efforts involved taking the mainboard which had a 44 Pin Edge Connector and discerning how to interface those 44 pins to make a working Transceiver. My mechanical band switch has 2 poles and 5 positions. One pole gives signals to change the Arduino/Si5351 to the various bands and the 2nd pole supplies power to banks of BPF's and LPF's. 

This is where being a real homebrewer versus a kit builder shows its true colors. There was no circuit board nor bags of parts supplied. The SS FPM-300 had to be designed and engineered. You also had to have skills with the CNC Mill. Those holes in the front panel were machine cut. The Dial Plate for the Band Switch was also made on the CNC. 

There are no Bitx20 circuits or TIA amps involved with the design, and it works just fine. 

Them that know can make it go.

73's

Pete N6QW

January 26, 2025. So, OK you just bought 100 pieces of the J310 SMD type--What Now?

Bi-Directional IF Amplifier Stage from G4GXO

So, you just popped for 100 Pieces of the SMD version of the J310 for about $20 and that is when you discovered that China didn't pay the 10% tariff -- you did. About $2 extra to buy 100 pieces. Stupid decisions have consequences! A Tip of the Cap to you MAGA-O-Lytes.

Now what do you do with those 100 Pieces? With due recognition to Ron Taylor, G4GXO who designed this circuit which appeared in SPRAT #128 you build it. Yes, it is a bilateral circuit and signal reversal is done with Voltage switching. If you are a serious homebrewer, then you need to join the G-QRP club and purchase the SPRAT on a Stick!

 

In case you bought the SMD version of the J310 it has a max voltage of 10 Volts and this circuit should work at 10 VDC -- it might need some resistor tweaking but don't fret it will work OK.

 

This circuit simulates a Dual Gate MOSFET and does have an advantage of being able to adjust the gain by what is applied to Gate #2. In several of my transceivers where I used this circuit, a relay applies AGC to Gate #2 on Receive but switches in a fixed voltage on Transmit for max gain.

With a bit of twizzling in LT Spice you could make this a single J310 but lose the ability for AGC or ALC or Fixed Gain at Gate#2. Since the J310s are in cascade, the current flow (current draw) is less than for two separate devices. 

This circuit has seen service in my Tri-Band SS HW-100 and the KWM-4. You can see the SS HW-100 at https://www.jessystems.com

So, another piece to homebrewing a rig that has a low current draw with flexibility and bilateral. No, this is not a Bitx Topology although most likely a (TIA) termination insensitive array. The 820 Ohm resistors across the Toroid windings force a 16:1 match -- yes in/out is 50 Ohms.

BTW a really cool side benefit is that when you apply AGC to Gate #2 and have the level set just right -- the LED's Blink/Wink and show the AGC action. See the video at about 1min 20sec.

When you know you can make things go!

73's

Pete N6QW

 

January 25, 2025. A QRP SDR Radio from Italy and Grocery Prices are Up!

Meet the ELAD, a QRP SDR from Italy

Having nothing in my refrigerator because of the PSPS I had to get some basic food stuffs like some milk and eggs.  It was sticker shock, like $7 for a dozen of eggs. The eggs I really like are close to $10 a dozen. 

This new administration is so focused on revenge, immigrant deportation and taking away our rights, it seems like fixing the food inflation would be job one. But then that is not as much fun as rounding up "those immigrants". 

Shades of the Chinese Exclusion Act. A funny story about that era. When I lived in Port Townsend (WA), there is a bit of history with that act. Many Chinese were employed building the railroad to Seattle. Job done the Chinese remained in the local area and even migrated to places like Port Townsend where they set up businesses like Prostitution and Laundries. The enactment of the Exclusion Act put a real kink in the local late-night entertainment and the outsourcing of clean clothes. BTW the Chinese Exclusion Act was the first piece of legislation to exclude a specific class of immigrants.

So back to radios. The gravity of the proposed tariffs is not well understood. Things will cost more, and the big-ticket items will be especially hit. I am still pondering a new car after 19 years. It is suggested that with the tariff's, car prices will be 10% higher. Even stuff made in America will see that rise because "Made in America" also means with some parts made offshore. It is a global economy! If you buy a new appliance box, no matter where made expect increased prices.

I am dumping Frontier as my Internet and one of my Phone service providers. It is a move I should have made about three years ago. So, I have to return some gear like the router. In looking at the info on the router name plate in small print are the words Made in Vietnam. 

Frontier also has a practice that is seedy. So, I called them about the disconnect and in the same call asked about a rebate for the days when there was no Internet because of PSPS. This is rich as I did have a rebate -- BUT it is not automatic. You must ask for it. I am getting a $15 credit. If you have Frontier, then give serious consideration to finding another carrier. Poor customer service and costly for just basic cable are the primary attributes. Star Link and T-Mobile Home Internet are currently being explored as the new service providers.

Back to our ELAD and take a hard look at the specs. The box has a clean design to it and that signals attention to detail. The small form factor should give rise for QRP POTA and SOTA use. Not a household name like FLEX or APACHE ANON, Sun SDR or ICOM IC7300 -- but there is room in the tent. It is not only a standalone radio but when you hook it up to a computer it is in the league of the FLEX or Apache Anon. About $1100 before the new Tariffs implode.

Them that know can make it go!

73's

Pete N6QW

January 24, 2025. We are Safe and Power Back On!

Ten hours without power and just a bit of spoiled food. The Laguna Fire was contained to about 94 acres and mostly open fields -- although threatening hundreds of millions of dollars' worth of produce growing in the Oxnard Plain.

This time I moved all of the stuff, which was pre-positioned, into the car and thought this might be the time. But God was with us. 

Also threatened was CSU Channel Islands which has an urban legend connection to the Eagles. This California State University was formerly a state mental hospital which was converted to the University. The connection is the song from the Eagles called "Hotel California". Legend has it the mental hospital was Hotel California.

Quick take a look at the SSB radio or Homebrew Rig sitting in front of you and give a tip of the cap to O.G. "Mike" Villard Jr. In 1947 Dr. Villard was a Professor of Electrical Engineering at Stanford and also W6OYT. It was in 1947 that he built and put on the air a homebrew SSB transmitter. That event marked the first ham SSB QSO. This rocked the ham bands, and the rest is history. A year later the transistor was invented. Fast forward a mere 10 years and we have the Collins KWM-1.

W6OYT is also credited in 1959 with developing over the horizon radar using the ionosphere as a reflecting mechanism. His PhD advisor while a student at Stanford was Dr. Fredrick Terman. For those who have an older EE Degree, Terman was the Oracle at Delphi. 

So that means that amateur radio SSB has been in work for some 78 years and some BTE's thought it was invented last year.

Them that know can make it go!

73's

Pete N6QW

January 23, 2025. Yet another Fire in the LA Area.

Breaking news.

Power outage and the Laguna Fire is 6 miles west of my house. Car is packed with only 1 Radio. If my home gets smoked then it's the end of my boat anchor collection.

An inconvenience but not the end of the world.

There was a popular song many moons ago by Johnny Cash called Ring of Fire. Well, there is a Ring of Fire around the Los Angeles Area. The latest is the Hughes Fire near Lake Castaic about 40 Miles NE from me. As usual a raft of PSPS texts, emails and even phone calls to expect my power to go down for the 4th time in two months. 

Hughes Fire ~ About 9000 Acres

This fire situation is great political fodder for what's his name, but the reality is that I keep nothing in the refrigerator, and I have my go stuff at the front door. But the Hughes Fire is different -- I can smell it, whereas the other fires in the ring were not smelly at this QTH. At 9000 acres burnt that comes to about 14 Square Miles. [9000*43560 / (5280^2) = 14.1 sq miles]

My battery is charged so I have Cell Phone and Laptop charging capabilities. In many respects having the XYL in a Board and Care facility is a plus as her location has had less PSPS shutdowns and there is staff there 24/7 and they have back up Oxygen systems. It would be impossible to care for her here at home with the power off for three or four days. Bright spot: Rain is expected this weekend.

I have simulated a J310 JFET general purpose amp stage using LT Spice. Indeed, the results looking promising and so a bit more work toward a low power consumption emergency rig. Too bad I keep having to delay things because of the PSPS situation.

 

 

 

This simulation is just a starting place as the simulation of the 500 Ohm filter is just a plug circuit to see if this could work. More simulation time is needed to accurately represent the actual 9 MHz filter and then see the gain across the module.

 

Them that know can make it go.

73's

Pete N6QW